*Change from 2006 to 2007
We based our rankings on the median home sales prices between July 2007 and June 2008 for each ZIP, as collected by First American CoreLogic, a national real estate data collection and research firm that tracks over 150 million parcels in over 3,000 counties, amounting to 99% of all real estate transactions. The data included all residential land transfers and all arms length transfers--a sale where the buyer and seller are not the same and price is greater than 3,000. ZIPs were ranked according to the median sales price.
Demographic information such as median income and population density are from the U.S. Census Bureau's most recent ZIP code survey. Densities are measured on a persons-per-square-mile basis and are rounded up to the nearest whole person.
In some cases, data were not available. These are marked N/A. Both median-income data and population-density data were calculated by the U.S. Census Office. In some cases, the Census Office did not release an estimate for these two figures due to trouble with reporting. In the case of absent year-over-year sales price changes, there were certain historical pricing data that were incomplete or that First American CoreLogic deemed unreliable. This could be due to reporting errors at the local level or not enough sales from the previous year to develop a reliable figure. In these cases, we calculated the year-over-year value change as zero.